The requirement to be able to measure the phase difference between two signals, for example two sinusoidal signals, occurs frequently in electronic systems. Examples of systems in which such measurements are needed are phase locked loops, PLLs, and in demodulation of phase-shift keyed signals, PSK-signals.
Known phase detectors include analog solutions such as Gilbert mixers and digital solutions such as logic circuit comprising logic gates and/or flip-flops. Such known solutions usually exhibit drawbacks either regarding the “phase region” or the frequency range in which they are effective.